10 Best Resignations of All Time

British Conservative politician Geoffrey Howe leaves his London home for the House of Commons, prior to giving his famous resignation speech criticizing Margaret Thatcher. With him is his wife Elspeth Howe. Peter Macdiarmid/Getty Images

Sir Geoffrey Howe was one of Margaret Thatcher's most loyal deputies, serving in the former U.K. prime minister's cabinet for three full terms. Thatcher was cruising to victory in a fourth general election when Howe drove a political dagger into her heart, albeit a very well-mannered British dagger.

In a 1990 televised speech before the full House of Commons, the bookish Howe announced his resignation from Thatcher's cabinet by criticizing her leadership style and condemning her opposition to a single European currency [source: BBC]. Even Howe's polite delivery couldn't hide his frustration with the direction taken by members of his own conservative Tory Party and the Iron Lady herself, who was squirming in the front row.

"The tragedy is -- and it is for me personally, for my party, for our whole people, and for my Right Honourable Friend herself, a very real tragedy -- that the Prime Minister's perceived attitude towards Europe is running increasingly serious risks for the future of our nation."

Howe's speech, which Thatcher later described as "an act of bile and treachery," triggered a dramatic turn in the controversial Prime Minister's political fortunes [source: Reuters]. The Tory Party split, and Thatcher was ousted from power a mere nine days later.